Three-dimensional Analysis on the Changes of Urban Greenery in Congested Residential Areas Using CAD Model

Abstract

This study aimed to analyze the changes of urban greenery in congested residential areas and its causes using the current photographs and the old ones. First, we developed a method to estimate the height, the crown area and the location of greenery by referring the signs or other objects in the photographs, and shooting points of pictures. Then, we established the 3D-CAD model of congested residential areas using pictures taken in 1991 and 2008, and figured out the three-dimensional changes of urban greenery. Through the analysis, the following findings were obtained; Alteration in the volume of greenery was bigger than the estimation from the analysis of the changes in green cover area. The changes of green volume were observed in the process of the replacement of buildings. And it was revealed that the decrease of the volume of the greenery was caused mainly by the loss of tall trees facing the roads.